Bug 2447382 (CVE-2026-29774)

Summary: CVE-2026-29774 freerdp: FreeRDP has a heap-buffer-overflow in avc420_yuv_to_rgb via OOB regionRects
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A heap based buffer overflow flaw has been discovered in FreeRDP. A client-side heap buffer overflow occurs in the FreeRDP client's AVC420/AVC444 YUV-to-RGB conversion path due to missing horizontal bounds validation of H.264 metablock regionRects coordinates. A malicious server can trigger a client-side heap buffer overflow (WRITE of 16 bytes via SSE), causing a crash (DoS) and heap corruption. The attacker controls the offset via the left coordinate, potentially enabling arbitrary write to adjacent heap objects with code-execution risk depending on allocator layout.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2447421, 2447424, 2447428    
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Description OSIDB Bzimport 2026-03-13 18:04:20 UTC 
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a client-side heap buffer overflow occurs in the FreeRDP client's AVC420/AVC444 YUV-to-RGB conversion path due to missing horizontal bounds validation of H.264 metablock regionRects coordinates.  In yuv.c, the clamp() function (line 347) only validates top/bottom against the surface/YUV height, but never checks left/right against the surface width. When avc420_yuv_to_rgb (line 67) computes destination and source pointers using rect->left, it performs unchecked pointer arithmetic that can reach far beyond the allocated surface buffer. A malicious server sends a WIRE_TO_SURFACE_PDU_1 with AVC420 codec containing a regionRects entry where left greatly exceeds the surface width (e.g., left=60000 on a 128px surface). The H.264 bitstream decodes successfully, then yuv420_process_work_callback calls avc420_yuv_to_rgb which computes pDstPoint = pDstData + rect->top * nDstStep + rect->left * 4, writing 16-byte SSE vectors 1888+ bytes past the allocated heap region. This vulnerability is fixed in 3.24.0.